System for controlling physical distribution pallets

ABSTRACT

The present invention provides a system for controlling physical distribution pallets, by which it is possible to accurately identify status of pallets, to set up an adequate forwarding plan of pallets, and to accomplish physical distribution in smooth manner. The system comprises wireless detecting means 22 mounted on pallets and for detecting pallet control information transmitted from transmitting means 21 which stores pallet control information of said pallet and transmits in wireless, pallet stock data storage means 23 for receiving and storing the pallet control information detected by the wireless detecting means via a wide area communication network, and pallet status judging means 24 for judging whether the pallet stored in memory of the pallet stock data storage means is empty or not based on the pallet control information of said pallet. Further, it comprises supply and demand predicting means 27 for predicting supply and demand of pallets at physical distribution bases and planning means 29 for setting up a forwarding plan for forwarding pallets at minimal cost between physical distribution bases. It is possible according to the present system to accurately identify the status of pallets, to set up an adequate forwarding plan for pallets, and to accomplish smooth physical distribution.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a transportation control system or asystem for controlling physical distribution pallets used in wide areaphysical distribution, and in particular to a system for controllingphysical distribution pallets, by which it is possible to adjustarrangement of pallets at each physical distribution base to facilitatesmooth physical distribution and to set up a forwarding plan to matchthe reality or to provide detailed control information.

2. Description of the Related Art

To control mobile objects or articles in facilities, a technique hasbeen known in the past, in which a transponding card, i.e. an IC cardprovided with wireless transmission and receiving functions is mountedon the mobile object or the article, and information such as positioninformation issued by the transponding card is collected at a center toidentify the position of the mobile object or the presence of the object(Japanese Patent Publications 5-35934 and 5-67091).

Also, as the technique relating to setting-up of forwarding plan oftransport container, the methods have been proposed for distributionplan of sea-borne containers "Imai, A. et al.: "A Study on the ShortPeriod Planning for the Distribution of Empty Sea-borne Containers",Navigation Association of Japan, No. 81, pp. 1-8, 1989) or for theforwarding plan of railroad containers (Fukumura, N.: Planning forForwarding of Empty Containers, Using a Mathematical ProgrammingMethod", RTRI Report, Vol. 8, No. 2, pp. 39-44, 1992).

For pallets, which are transport containers in wide area distribution,it is necessary for maintaining smooth physical distribution to identifyquantity of pallets in stock at each physical distribution base and tokeep sufficient quantity of pallets to match the transport quantity ofthe articles. At present, stock control of this type of pallets iscarried out by human power.

On the other hand, various types of systems to set up transport planningof freight and containers have been conceived under computer-aideddesign. A system for setting up transport planning through interactivetransaction with users is proposed in Japanese Patent PublicationLaid-Open 62-1070. Japanese Patent Publication Laid-Open 6-259411discloses a system of agent model, in which a plurality of processingmodules are provided to set up transport planning of objects to betransported in each transport medium, and transport schedule is preparedthrough information exchange between the modules.

In the physical distribution field, a new mode of freight transportationis increasingly introduced in recent years, which uses pallets tofacilitate the execution of loading and unloading operation. The palletsare carried to various places all over the country with cargoes placedon them. After unloading the cargoes, the pallets are sent to the otherplaces with new cargoes placed on them. However, freight transportationis usually one-way transportation from a place of supply to a place ofdemand, and good balance is not always kept in transportation quantitybetween these areas. As a result, there are a lot of empty palletsstagnated at a distribution base, while pallets for loading cargoes arein shortage in another distribution base. For this reason, it isnecessary to constantly control the stock of pallets and to send emptypallets from an area where pallets are in excess to an area wherepallets are in shortage.

The sending of empty pallets may be too late if it is carried out afterfinding out that pallets are in shortage. The needed quantity of palletsmust be transported in advance. It is necessary to predict freighttransport quantity at each physical distribution base so that noinconvenience or trouble occurs in freight transportation. Also, thebest route of transportation must be selected to reduce the cost forsuch transportation.

There are the following references discussing the transportation ofcontainers and pallets: Kojima, K. et al.: "The Building of a SimulationSystem for Prediction of the Number of Necessary Pallets", Kato, S. etal.: "A Study on Pallet Transportation Problem" (50th NationalConference of Information Processing Society), or Fukumura: "Planningthe Forwarding of Empty Containers, Using a Mathematical ProgrammingMethod", (RTRI Report, Vol. 8, No. 2, February 1994). In the lastreference, description is given on a technique to plan the forwarding ofempty containers, based on a mathematical programming method usingmodel.

In the conventional methods, however, it is not possible to solve theproblems related to the control of pallets in wide area physicaldistribution as described below. In the wide area physical distribution,there are tremendous quantity of pallets in distribution, and it is alsovery difficult to uniformly perform stock control of these pallets athigh accuracy because the pallets are to be distributed all over thecountry.

Even if a pallet is present, it cannot be utilized immediately fortransportation of freight unless it is empty. In the conventionalmethod, it is not possible to automatically identify whether the palletsare empty or not. In wide area physical distribution, it is difficult toaccurately predict supply and demand of pallets used for transportation.This is because the forwarding business is to forward freight at therequest of each customer, and it is difficult to predict the quantity offreight to be forwarded. The differences in areas or seasonal variationsalso exert extensive influence on supply and demand of pallets.

When a number of empty pallets are present far away from an area wherepallets are wanted, it is necessary to forward the empty pallets and tooptimize the arrangement of pallets at each distribution base, but ittakes high cost for forwarding because the range of forwarding coversthe whole country. It is an important problem to set up a forwardingplan to minimize the forwarding cost. The forwarding of empty palletsmay be too late if it is carried out after finding out that the emptypallets are in shortage. It is also important which route oftransportation should be used to optimize the forwarding of emptypallets to the destination.

When it is actually attempted to set up a plan for forwarding emptypallets, such plan must be considered in view of distribution bases allover the country. Unlike the case where a model is used, the scale ofcalculation is very extensive, and the time of calculation alsoincreases.

In the pallet control as it is carried out, very elaborate control isrequired, i.e. to accurately identify actual status of pallets, and toestimate demand on pallets in very short time span. Based on theresults, the schedule of forwarding or the time of departure and arrivalmust be set up, or adequate standard for pallets in stock must bedetermined. To set up the plan to forward pallets, full considerationmust be given on the mode of transportation of the distribution or onforwarding companies and customs and practice in the forwardingbusiness.

SUMMARY OF THE INVENTION

To solve the above problems, it is a first object of the presentinvention to provide a system for. controlling physical distributionpallets, by which it is possible to accurately identify the status ofpallets, to set up an adequate plan for forwarding pallets and to carryout physical distribution in smooth manner.

To attain the first object of the invention, the transport controlsystem for controlling pallets used for transportation of freight inwide area physical distribution comprises transmitting means mounted onthe pallets and for storing and transmitting pallet control informationof the pallets in wireless, wireless detecting means for detecting thepallet control information transmitted from the transmitting means,pallet stock data storage means for receiving and storing the palletcontrol information detected by the wireless detecting means via a widearea communication network, and pallet status judging means for judgingwhether the pallet stored by the pallet stock data storage means isempty or not based on the pallet control information for that particularpallet.

A preferred aspect of the present invention comprises supply and demandpredicting means for predicting supply and demand of pallets at physicaldistribution bases and forwarding plan setting means for setting up aforwarding plan to forward pallets between a plurality of distributionbases where pallets are in excess and a plurality of distribution baseswhere pallets are in shortage at minimum cost. This makes it possible toaccurately identify conditions of the pallets, to set up adequateforwarding plan of pallets and to accomplish smooth physicaldistribution.

Further, to solve the problems for forwarding pallets as describedabove, it is a second object of the present invention to provide asystem for controlling physical distribution pallets, by which it ispossible to elaborately control stock quantity of the pallets and to setup a realistic forwarding plan of the pallets.

To attain the second object of the invention, the system for controllingphysical distribution pallets according to the present inventioncomprises a user interface for accepting requests of users and fordisplaying the pallet forwarding plan thus set up, a wireless tag devicefor automatically acquiring information relating to arrival anddeparture of pallets, accumulating means for accumulating information ofthe pallets acquired and information on the pallet forwarding plan, anda system main unit for reading the information of the accumulating meansand setting up pallet forwarding plan as requested by the user, wherebythe system main unit is provided with various types of forwarding plansetting means and simulating means for reading information of theaccumulating means to cope with diversified requirements of the users.

As a result, it is possible to achieve reliable stock control of thepallets in actual wide area physical distribution, to set up theforwarding plan, and to efficiently carry out the physical distributioncontrol.

The invention according to claim 1 provides a transport control systemfor controlling pallets used in transport of freight in wide areadistribution, and the system comprises transmitting means mounted oneach of pallets and for storing and transmitting pallet controlinformation of the pallets in wireless, wireless detecting arrive bytransport means and the quantity of pallets to leave and also on thecurrent quantity of pallets in empty state, whereby the quantity ofpallets needed at the physical distribution base can be quantitativelypredicted.

In the invention according to claim 5, the supply and demand predictingmeans compensates the predicted quantity of pallets in excess or inshortage based on knowledge or constraint condition relating to supplyand demand of pallets, and it is possible to increase accuracy of thepredicted value.

In the invention according to claim 6, there is provided forwarding plansetting means for setting up forwarding plan of pallets between physicaldistribution bases according to the supply and demand predicting data ofthe pallets obtained by the supply and demand predicting means andknowledge or constraint condition on supply and demand of the pallets,whereby it is possible to set up forwarding plan of the pallets, whichcan generally correct shortage or excess of the pallets at each physicaldistribution base and also to reduce the number of personnel to beassigned for setting up the forwarding plan.

In the invention according to claim 7, the forwarding plan setting meanssets up forwarding destination, forwarding quantity and time offorwarding to minimize the forwarding cost between a plurality ofdistribution bases where pallets are in excess and a plurality ofdistribution bases where pallets are in shortage, whereby it is possibleto minimize the cost needed for the forwarding of the pallets.

The invention according to claim 8 comprises a transport network storagemeans for hierarchically arranging and storing information relating totransport network, which hierarchically connects physical distributionbases, and the forwarding plan setting means uses the data stored in thetransport network storage means when setting up the forwarding plan ofthe pallets, and it is possible to set up a forwarding plan for thepallets suitable for transport network in wide area physicaldistribution.

In the invention according to claim 9, transport network storage meansclassifies the data relating to the transport network to major transferbases, general transfer bases and collection and delivery bases andstores hierarchically based on function of the physical distributionbases, whereby it is possible to set up a forwarding plan of palletssuitable for transport network having hierarchical structure in widearea physical distribution.

In the invention according to claim 10, there are provided map storagemeans for storing road maps and route searching means for searching anoptimal transport route to the forwarding destination of a pallet basedon the pallet forwarding plan data set up by the forwarding plan settingmeans and the data of the map storage means, whereby it is possible toindicate an optimal transport route to the forwarding destination evenwhen a driver in charge of transporting empty pallets does not have goodknowledge about the forwarding destination.

In the invention according to claim 11, there is provided a system forcontrolling physical distribution pallets for controlling stock ofpallets in wide area physical distribution and for setting up a palletforwarding plan, and the system comprises a user interface for acceptingrequest of users and for indicating a pallet forwarding plan thus setup, a wireless tag device for automatically acquiring informationrelating to arrival and departure of pallets, accumulating means foraccumulating information of the acquired pallet and information of thepallet forwarding plan, and a system main unit for reading theinformation of the accumulating means and for setting up the palletforwarding plan as requested by the users, whereby it is possible to setup diversified pallet forwarding plans as requested by the users and topresent the plans to the users based on pallet control informationautomatically collected. terms of time at each distribution base,whereby it is possible to indicate the quantity of pallets to beprepared at each physical distribution base.

In the invention according to claim 19, the system main unit comprisesstandard stock quantity automatic judging means for indicating palletforwarding plan in case standard stock quantity of pallets at physicaldistribution bases is specified using the standard stock quantityjudgment supporting means and the schedule interval judgment supportingmeans, whereby the user can find how the pallets are forwarded in casethe standard stock quantity at the physical distribution base has beenchanged.

In the invention according to claim 20, the system main unit compriseshierarchical planning means for hierarchically setting up the plan bydividing the physical distribution bases to those between districts andthose within a district and by sorting the pallet forwarding plan to aplan between districts and a plan within a district, whereby it ispossible to set up a pallet forwarding plan to cope with physicaldistribution network.

In the invention according to claim 21, the system main unit comprisesactual result data automatic collecting means for converting informationobtained from the wireless tag device to pallet control information,whereby it is possible to convert the actual status of pallets to data.

In the invention according to claim 22, the wireless tag device isdesigned in such manner that place of departure and place of arrival ofpallets and time of departure and time of arrival are inputted to actualresult data automatic collecting means, whereby it is possible to inputimmediate information of pallets.

BRIEF DESCRIPTION OF THE DRAWINGS

These objects and features of the present invention will become morereadily apparent from the following detailed description of thepreferred embodiments taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is a block diagram of a first embodiment of a system forcontrolling physical distribution pallets according to the presentinvention;

FIG. 2 represents tables showing examples of memory content in a palletstock storage area in the above system for controlling physicaldistribution pallets;

FIG. 3 is a flow chart showing a processing procedure of pallet statusjudging means in the above system for controlling physical distributionpallets;

FIG. 4 represents a table showing an example of memory content in atransport schedule storage area in the above system for controllingphysical distribution pallets;

FIG. 5 represents tables showing examples of memory contents ofknowledge storage area in the above system for controlling physicaldistribution pallets;

FIG. 6 is a flow chart of a processing procedure of supply and demandpredicting means in the above system for controlling physicaldistribution pallets;

FIG. 7 is a diagram showing display mode of the results of supply anddemand prediction in the above system for controlling physicaldistribution pallets;

FIG. 8 shows examples of memory contents in transport network storageareas in the above system for controlling physical distribution pallets;

FIG. 9 is an image drawing to show hierarchical structure of thetransport network storage area of the above system for controllingphysical distribution pallets;

FIG. 10 is a flow chart of a processing procedure of forwarding plansetting means in the above system for controlling physical distributionpallets;

FIG. 11 is a diagram showing display form of the results of forwardingplan set-up in the above system for controlling physical distributionpallets;

FIGS. 12A, 12B and 12C each represents an example of memory content in amap storage area in the above system for controlling physicaldistribution pallets;

FIG. 13 is a flow chart of a processing procedure of route searchingmeans in the above system for controlling physical distribution pallets;

FIG. 14 is a drawing to show display form-of the results of routesearching in the above system for controlling physical distributionpallets;

FIG. 15 is a general block diagram of a second embodiment of a systemfor controlling physical distribution pallets according to the presentinvention;

FIG. 16 is a flow chart in high-speed plan setting means;

FIG. 17 is a flow chart in forwarding service judging means;

FIG. 18 is a flow chart in pallet quantity predicting means;

FIG. 19 is a diagram of approximate function of pallet data predicted bypallet quantity predicting means;

FIG. 20 is a flow chart in actual result feedback means;

FIG. 21 is a flow chart in schedule interval judgment supporting means;

FIG. 22 is a flow chart in schedule interval automatic judging means;

FIG. 23 is a flow chart in standard stock quantity judgment supportingmeans;

FIG. 24 is a flow chart in standard stock quantity automatic judgingmeans;

FIG. 25 is a flow chart in hierarchical planning means;

FIG. 26 is a flow chart in actual result data automatic collectingmeans;

FIG. 27 represents data on transport costs between physical distributionbases;

FIG. 28 represents data of pallets in excess or in shortage betweenphysical distribution bases;

FIG. 29 represents data of pallets in excess or in shortage at each ofphysical distribution bases;

FIG. 30 represents data of transport costs between physical distributionbases;

FIG. 31 represents data of a supply and demand table;

FIG. 32 represents input equations to linear programming means;

FIG. 33 represents output equations to linear programming means;

FIG. 34 represents data obtained by converting output of the linearprogramming means;

FIG. 35 represents pallet data at Asahikawa;

FIG. 36 represents complementary difference at each of thephysical-distribution bases;

FIG. 37 represents data of pallets in excess or in shortage between thephysical distribution bases;

FIG. 38 represents a supply and demand table between the physicaldistribution bases;

FIG. 39 represents input equations of linear programming means;

FIG. 40 represents output equations of linear programming means;

FIG. 41 represents quantity of pallets at every hour at a physicaldistribution base;

FIG. 42 is a table showing standard stock quantity and excess orshortage data between the physical distribution bases;

FIG. 43 represents a timetable of transport services;

FIG. 44 shows default values of standard stock quantity;

FIG. 45 represents excess or shortage data with the standard stockquantity as a variable;

FIG. 46 represents data after change of the excess and shortage data;

FIG. 47 represents data in each of delivery districts;

FIG. 48 represents data for each delivery district; and

FIG. 49 represents actual result data from the wireless tag.

DETAILED DESCRIPTION OF THE INVENTION

In the following, description will be given on the preferred embodimentsof a system for controlling physical distribution pallets of the presentinvention referring to the drawings.

1st Embodiment

FIG. 1 is a block diagram showing a first embodiment of a system forcontrolling physical distribution pallets of the present invention. Asshown in FIG. 1, this system for controlling physical distributionpallets can communicate with a wireless tag 21, which is mounted on eachpallet and stores and transmits pallet control information forindividually controlling the pallets. The system for controllingphysical distribution pallets shown in FIG. 1 comprises wirelessdetecting means 22 for reading and writing pallet control information inwireless from or to the wireless tag 21, pallet stock storage means 23for collecting and storing pallet control information obtained by thewireless detecting means 22 via a wide area communication network 55 andan interface 56 connected thereto, pallet status judging means 24 forjudging whether a pallet is empty or not from the pallet controlinformation, transport schedule storage means 25 for storing informationrelating to schedule of transport services, knowledge storage means 26for storing knowledge and constraint condition relating to supply anddemand of pallets, supply and demand predicting means 27 for predictingsupply and demand of pallets for each physical distribution baseaccording to the pallet supply and demand data stored in the palletstock storage means 23, schedule data stored in the transport schedulestorage means 25, and data stored in the knowledge storage means 26,transport network storage means 28 for hierarchically arranging andstoring information relating to transport network, which connects thephysical distribution bases, forwarding plan setting means 29 forsetting up pallet forwarding plan between the physical distributionbases from the pallet supply and demand predicting data outputted fromthe supply and demand predicting means 27, the data stored in theknowledge storage means 26, and the data stored in the transport networkstorage means 28, map storage means 50 for storing road maps, routesearching means 51 for searching an optimal transport route to theforwarding destination from the pallet forwarding plan data outputted bythe forwarding plan setting means 29 and the map data stored in the mapstorage means 50, and a result display unit 52 for displaying theresults obtained by the means 27, 29 and 51. Further, there is providedinstruction input means 57 for inputting and giving instructions fromthe user to each of these means.

The wireless tag 21 mounted on each pallet consists of an IC cardprovided with transmitting and receiving functions. It stores palletcontrol information such as pallet ID for individually identifying thepallets and transmits the stored pallet control information at therequest to read from the wireless detecting means 22.

The wireless detecting means 22 is installed at each physicaldistribution base, reads pallet control information from the wirelesstag 21 of a pallet to arrive or to depart, and transmits the palletcontrol information together with position information indicating thephysical distribution base where the wireless detecting means 22 isinstalled and also with the information on the detecting time to acenter via a wide area communication network 55. Here, the physicaldistribution bases mean major transfer bases (physical distributioncenters) shown in FIGS. 8 and 9 and general transfer bases (businessoffices) organized under the major transfer bases. Each of thesephysical distribution bases has parking space for trucks,.whichtransport pallets and articles or products accommodated on the pallets.When the truck arrives at the physical distribution base, the loadedpallets are unloaded from the truck, the truck passes through apredetermined gate. An antenna (not shown) of the wireless detectingmeans 22 is mounted on each gate or nearby, and when the pallet passesthrough the gate, communication is performed between the wirelessdetecting means 22 and the wireless tag 21.

The wide area communication network 55 is a network to concentrateinformation from the wireless detecting means 22 located at all physicaldistribution bases covered by the present system via a special-purposeline or via cable communication means such as public line. The wide areacommunication network 55 is connected to the pallet stock storage means23 via the interface 56. Except the wireless detecting means 22, each ofthe means 23 to 29, 50 and 51 shown in FIG. 1 comprises a centralprocessing unit (CPU) (not shown), memory such as ROM and/or RAM and anexternal storage unit. If necessary, a digital signal processor (DSP)may be used. The result display unit 52 is provided with a CRT, a liquidcrystal monitor and a drive unit. In FIG. 1, the components enclosed bydotted line is provided at the center. These means may be a personalcomputer or a work station, comprising 32-bit CPU with clock frequencyof 100 MHz.

As shown in FIG. 2, the pallet stock storage means 23 accommodates apallet movement control table comprising a pallet ID field to describeID of each pallet, a position information field to describe position ofa pallet, a detection time field to describe the time when palletcontrol information is received from the wireless tag, and a palletstatus field to describe status of each pallet, and an empty palletstock table comprising a physical distribution base field to describethe physical distribution base, an empty pallet standard stock quantityfield to describe standard stock quantity of empty pallets at thephysical distribution base, and an empty pallet current quantity fieldto describe current quantity of the empty pallets. The current quantityof empty pallets in the empty pallet stock table is calculated from thedata of the pallet status field of the pallet movement control table.

The pallet status judging means 24 prepares the data of the palletstatus field of the pallet movement control table based on the detectiontime of the pallet movement control table stored in the pallet stockstorage means 23 by the procedure of the flow chart shown in FIG. 3.

In Step 0, the pallet control information detected by the wirelessdetecting means 22 is received via the wide area communication network.When it is stored in the pallet stock storage means 23, the palletstatus judging means 24 is started.

In Step 1, the pallet status judging means 24 judges whether the samepallet ID as the pallet ID to be written newly is already present in thepallet movement control table. If it is present, the status of thepallet to be newly written is determined as "departure" in Step 2. Thisis written to the pallet movement control table, and the processing iscompleted in Step 5. (The data of the pallet in "departure" status iserased from the pallet movement control table after a predetermined timehas elapsed.)

If the same pallet ID as the pallet ID to be newly written is notpresent in the pallet movement control table in Step 3, the status ofthe pallet to be written newly is determined as "arrival". This iswritten in the pallet movement control table. For the pallet, which hasbeen determined as in "arrival" status in Step 4, the status isdetermined as "empty" after the standard time required for unloading offreight has elapsed. This value is written in the pallet movementcontrol table, and processing is completed in Step 5.

The system may also be designed in such manner that pallet positioninformation showing the present position of the pallet or timeinformation showing time of departure or arrival of the pallet iswritten by a wireless device, and the information written on thewireless tag 21 or pallet ID information may be read by the wirelessdetecting means 22 installed at another position.

As shown in FIG. 4, the transport schedule storage means 25 accommodatesa transport schedule table, which comprises a transport service namefield, a transport departure place field, a transport arrival placefield, a departure time field, an arrival time field, and an averageloaded pallet quantity field.

As shown in FIG. 5, a transport knowledge table where transportknowledge is to be described and a constraint table where constraintrule is to be described are accommodated in the knowledge storage means26, and each of these tables comprises a rule number field, a conditionunit field, and an execution unit field.

The supply and demand predicting means 27 refers to the data of thepallet stock storage means 3, the transport schedule storage means 25,and the knowledge storage means 26 at the time when inventory of palletstock as determined in advance is performed, and predicts supply anddemand of pallets based on that time by the procedure shown in FIG. 6.The results are displayed on the result display unit 52.

When started in Step 6, the supply and demand predicting means 7 selectsphysical distribution base one each from the empty pallet stock table inthe pallet stock storage means 23 in Step 7. In Step 8, using thetransport schedule table of the transport schedule storage means 25, allof the average quantities of loaded pallets on the record where the nameof the physical distribution base selected in Step 7 is the same as thevalue at the place of arrival are added, and the predicted quantity ofpallets expected to arrive at the physical distribution base isobtained. In Step 9, all of the average quantities of loaded pallets onthe record where the name of physical distribution base selected in Step7 is the same as the value at the place of departure of the transportschedule table are added, and the predicted quantity of pallets expectedto depart at that distribution base is obtained. In Step 10, thepredicted quantity of pallets to depart as obtained in Step 9 issubtracted from the predicted quantity of pallets to arrive as obtainedin Step.8, and the predicted quantity of the pallets required on thenext day is obtained. In Step 11, the current quantity of empty palletsis subtracted from the standard stock quantity of empty pallets in theempty pallet stock table of the pallet stock storage means 3, and thecurrent quantity of pallets in excess or in shortage at the distributionbase selected in Step 7 is obtained. In Step 12, the predicted quantityof pallets needed on the next day as obtained in Step 10 is subtractedfrom the current quantity of pallets in excess or in shortage asobtained in Step 11, and the quantity of pallets in excess or inshortage at the standard time (e.g. 15:00) is obtained. In Step 13,referring to the data in the transport knowledge table of the knowledgestorage means 6, the quantity of pallets in excess or in shortage on thenext day as obtained in Step 12 is corrected when necessary.

In Step 14, it is checked whether there is a physical distribution base,for which supply and demand prediction has not been performed, in theempty pallet stock table of the pallet stock storage means 3. If thereis, the processing should be repeated from Step 7. If not, the resultsof supply and demand prediction for each physical distribution base aredisplayed in Step 15 by dotted line and black spot being continuous tothe past results in FIG. 7 (In FIG. 7, the difference from the standardstock quantity of empty pallets indicates the quantity of pallets inexcess or in shortage on the next day.), and the processing is completedin Step 16.

The transport network storage means 28 accommodates a major transferbase layer table comprising a major transfer base name field and asubordinate base, a general transfer base table comprising a superiorbase field and a subordinate base field, and a collection and deliverybase table comprising a collection and delivery base name field and asuperior base name field. Each of the major transfer base name, thegeneral transfer base name and the collection and delivery base namecorresponds to a node as an element to constitute the transport network.(This is called "transport node" to discriminate from the node toindicate road.) When taking notice of the difference of physicaldistribution functions, this can be classified into three categories.Major transfer base (main hub) is a base having transfer function ofphysical distribution in a wide area (e.g. on prefecture level). Generaltransfer base (hub), which has no collection and delivery function tocustomers is a base having transfer function of physical distribution inan area closer to the place of collection and delivery, fractionalizingthe wide area, and has no base for collection and delivery to customers.The collection and delivery base (depot) is a base having the functionof collection and delivery, receiving orders from customers anddelivering or collecting freight to and from customers. These bases havehierarchical structure as shown in FIG. 9. Actual, transportation iscarried out in such pattern as: Collecting freight from customers ∃Collection and delivery base (dept) ∃ General transfer base (hub) ∃Major transfer base (main hub) ∃ General transfer base ∃ Collection anddelivery base ∃ Delivery to customers. This takes typical transportationpattern in wide-area physical distribution and transportation ascommonly seen in mailing and express delivery service.

The forwarding plan setting means 29 sets up an optimal forwarding planof pallets, i.e. a forwarding plan to minimize the forwarding cost basedon the results of the pallet supply and demand prediction by theprocedure shown in FIG. 10, referring to the data of the knowledgestorage means 26, the supply and demand predicting means 27, and thetransport network storage means 28. The results are displayed on theresult display unit 52. Here, the empty pallet forwarding plan means aplan to obtain number of transport vehicles, transport schedule androute in case empty pallets are transported (forwarded) to the physicaldistribution base where pallets are in shortage from the physicaldistribution base where pallets are in excess based on the quantity ofpallets in excess or in shortage at each physical distribution basedetected as the results of supply and demand prediction.

When started in Step 17, the forwarding plan setting means 29 reads thepallet supply and demand prediction data at the physical distributionbases classified as major transfer base layer by the transport networkstorage means 28 in Step 18 and kept in memory from the supply anddemand predicting means 27. In Step 19, the constraint is read from theconstraint table of the knowledge storage means 26. In Step 20, this isformulated as a problem of linear programming in the mathematicalprogramming method based on the pallet supply and demand prediction dataread in Step 18 and the constraint read in Step 19, and the optimalsolution to minimize the pallet forwarding cost is obtained.Specifically, it is determined how many pallets should be forwarded fromwhich of the major transfer bases where empty pallets are in excess tothe major transfer base where pallets are in shortage.

Next, in Step 21, the pallets supply and demand prediction data of thephysical distribution base classified and stored as general transferbase layer in the transport network storage means 28 is read from thesupply and demand predicting means 27. In Step 22, the applicableconstraint is read from the constraint table of the knowledge storagemeans 26. In Step 23, the pallet supply and demand data at each physicaldistribution base as obtained as the result of the forwarding plan atthe major transfer base layer obtained in Step 19 is referred. If thereare major transfer bases where pallets are in shortage, these are addedas the object of the forwarding plan of general transfer base layer andare expressed as constraint. In Step 24, this is formulated as linearprogramming problem based on the pallet supply and demand predictiondata as read in Step 21 and on the constraint read in Steps 22 and 23,and the optimal solution to minimize the forwarding cost is obtained.Specifically, it is determined how many pallets should be forwarded fromthe general transfer bases where empty pallets are in excess to generaltransfer bases where pallets are in shortage. If there are bases wherethe problem of excess of shortage is not yet solved in the majortransfer base layer, this is considered as an object for forwarding.

Next, in Step 25, the pallet supply and demand prediction data of thephysical distribution bases, classified and stored as collection anddelivery base layer in the transport network storage means 28, is readfrom the supply and demand predicting means 27. In Step 26, theapplicable constraint is read from the constraint table of the knowledgestorage means 26. In Step 27, the forwarding plan in the generaltransfer base layer as obtained in Step 24 is referred as constraint. InStep 28, this is formulated as linear programming problem based on thepallet supply and demand prediction data as read in Step 25 and on theconstraint as read in Steps 26 and 27, and the optimal solution tominimize the forwarding cost is obtained.

In Step 29, the results of the forwarding plan setup is displayed in theresult display unit 52 shown in FIG. 11. (In FIG. 11, arrows indicateforwarding departure points and forwarding arrival points, and thenumber attached to each arrow indicates the quantity of pallets to beforwarded.) In Step 30, processing is completed.

In the map storage means 50, the following two tables are accommodated:a node table comprising a node name field to describe node name ofnetwork branch, a longitude field to describe geographical longitude ofnode, and a latitude field to describe latitude of the node, and an arctable comprising an arc name field to describe route between nodes, astarting point field to describe the node of the starting point of theroute, a terminal point field to describe the node of terminal point ofthe route, and a distance field to describe distance of the route.Further, a transport node correspondence table is accommodated in themap storage means 50 as shown in FIG. 12C. Describing this in detail,major transfer base, general transfer base and collection and deliverybase to express nodes of the transport network are called"transportation node" to distinguish them from the node on map. Toindicate correspondence between the transport node and the road map, thetransport node correspondence table is provided as shown in FIG. 12C.

The route searching means 51 searches a transport route having theshortest distance from the pallet forwarding starting point to thepallet forwarding arrival point by the procedure shown in FIG. 13,referring to the data of the forwarding plan setting means 29 and themap storage means 50. The results are displayed on the result displayunit 52.

When the route searching means 51 is started in Step 31, data is readfrom the map storage means 50 in Step 32. In Step 33, the forwardingplan setting results are read from the forwarding plan setting means 29.In Step 34, one of the forwarding plan setting results read in Step 33is selected. In Step 35, the shortest route from the forwarding startingpoint to the forwarding arrival point is detected referring to the arctable of the map storage means 50. In Step 36, it is checked whetherthere remains data, for which route searching is not yet performed amongthe forwarding plan setting results as read in Step 33. If data remains,the processing from Step 34 is repeated. If there is no remaining data,the results of route searching are displayed on the result display unit52 as shown in FIG. 14 in Step 37, and the processing is completed inStep 38.

2nd Embodiment

As shown in FIG. 15, the second embodiment of the system for controllingphysical distribution pallets of the present invention comprises asystem main unit 10 for setting up a pallet forwarding plan, a userinterface (UI) 20 for accepting requests of users and for displaying theresult of planning determined by the system main unit 10, a wireless tagdevice 41 for automatically acquiring information relating to arrivaland departure of pallets to and from stock, a storage unit 31 forstoring initial data, a storage unit 32 for storing actual result datashowing the current status of the pallets, and a storage unit 33 forstoring results of the pallet forwarding plan. In the initial datastorage unit 31, initial values such as data of transport services inphysical distribution, transport cost between physical distributionbases, pallet standard stock quantity at each physical distributionbase, delivery schedule interval of the forwarded pallets, etc. arestored. The wireless tag device 41 corresponds to the wireless detectingmeans 22 as explained in connection with FIG. 1, and it can communicatewith the system main unit via a wide area communication network (notshown). In FIG. 15, the wireless tag is not shown, but each pallet isprovided with a wireless tag, which communicate with the wirelessdetecting means 22 as shown in FIG. 1.

As each of the storage units 31 to 33, a magnetic disk or anopto-magnetic disk unit or RAM my be used. The user interface 20comprises an operation panel and a monitor unit such as CRT.

The system main unit 10 comprises high-speed planning means 11 forsetting up pallet forwarding plan at high speed, forwarding servicejudging means 12 for judging number of forwarding services of palletsand the quantity of the pallets to be forwarded in detail, palletquantity predicting means for predicting quantity of pallets-at anarbitrary time point at each of the physical distribution bases, actualresult feedback means 14 for reflecting the forwarding plan thus set upto the data of pallet supply and demand quantity in the delivery plan onthe next delivery day, schedule interval judgment supporting means 15Afor simulating the forwarding plan and for supporting judgment of palletforwarding schedule interval, schedule interval automatic judging means15B for judging pallet forwarding schedule interval using the scheduleinterval judgment supporting means 15A, standard stock quantity judgmentsupporting means 16A for supporting judgment on standard stock quantityat each physical distribution base by simulating the forwarding plan,standard stock quantity judgment supporting means 16B for judgingstandard stock quantity at each physical distribution base using thestandard stock quantity judgment supporting means 16A, hierarchicalplanning means 17 for setting up hierarchical delivery plan based onhierarchical structure between physical distribution bases, actualresult data automatic collecting means 18 for collecting informationfrom the wireless tag device 41, and a storage area 19 used as workingarea of each of these means. As already explained in connection withFIG. 1, each of the means 11 to 14, 15A, 15B, 16A, 16B, 17, and 18 ofthe system main unit 10 comprises CPU, memory such as ROM, interface,etc. The storage area 19 comprises memory such as RAM.

Next, description will be given on operation of each means of thissystem. When it is necessary to quickly determine the pallet forwardingplan, the user starts the high-speed planning means 11. The high-speedplanning means 11 sets up a pallet forwarding plan at high speed inaccordance with the flow chart of FIG. 16.

When the high-speed planning means 11 is started by UI 20 in Step 1100,data stored in the initial data storage unit 31, the actual result datastorage unit 32 and the planning result storage unit 33 are read intothe storage area 19 in Step 1110.

In this case, for example, transport cost data between physicaldistribution bases shown in FIG. 27 is read from the initial datastorage unit 31. From the planning result storage unit 33, the data onquantity of pallets in excess or in shortage. (hereinafter referred as"quantity in excess or shortage") of pallets to standard stock quantitydata for the planned days at each physical distribution base are read.(The quantity in excess or shortage is prepared by the pallet quantitypredicting means 13.)

In Step 1120., the high-speed planning means 11 classifies each baseinto place of demand and place of supply based on the data, and demandarray and supply array are prepared respectively. In Step 1130, theplaces of supply are sorted in the order from those with the lowertransport cost to the higher from j-th place of demand to each place ofsupply. In the present example, the places of demand are Aomori, Moriokaand Yamagata, and the place of supply is Sendai.

In Step 1140, pallet forwarding services are generated until demandquantity at the place of demand is turned to 0 or the supply quantity atthe place of supply is turned to 0 from the place of supply "k" to theplace of demand "j". In Step 1150, it is judged whether the demand atthe place of demand has been turned to 0 or not. If it is 0, it isjudged in Step 1155 whether the demand at the place of demand has beenturned to 0 or not. If not, returning to Step 1130, the processing fromStep 1140 is carried out for the next place of demand "j (1".

If demand at the place of demand has not,been turned to 0 in Step 1150,it is judged in Step 1160 whether supply quantity at all places ofsupply have been turned to 0 or not. If not turned to 0, returning toStep 1140, the pallet forwarding service from the next place of supply"k (1" to the place of demand "j" is generated. When supply quantity atall places of supply have been turned to 0, it is judged in Step 1170whether the period in question has been terminated or not. Ifterminated, all processings are completed in Step 1180. If notterminated, returning to Step 1120, processing for the next day iscarried out.

In Step 1155, if demand quantities at all places of demand are 0, theprocessing on i-th day is completed, and it is turned to Step 1170. Thepallet forwarding services determined by the high-speed planning means11 is stored in the planning result storage unit 33 and is presented tothe user via UI 20.

As described above, the high-speed planning means 11 determines palletforwarding destination and physical distribution base in the order fromthe lower transport cost to the higher transport cost based on thetransport fee between physical distribution bases. Because it isdetermined according to simple rule, it is possible to process at highspeed. When it is necessary to set up a general pallet forwarding planbetween a number of physical distribution bases, the user starts theforwarding service judging means 12. The forwarding service judgingmeans 12 determines number of pallet forwarding services or quantity ofpallets to be forwarded in accordance with the flow chart of FIG. 17.

When started by UI 20 in Step 1200, the forwarding service judging means12 reads the data stored in the initial data storage unit 31, the actualresult data storage unit 32 and the planning result storage unit 33 inStep 1210. In this case, for example, the data of standard stockquantity data and quantity in excess or shortage of pallets at eachphysical distribution base shown in FIG. 29 and transport cost databetween physical distribution bases shown in FIG. 30 are inputted asdata.

In Step 1215, the plan for the first day is set up at first to prepareplanning for "n" days. The quantity in excess or shortage on the firstday at each physical distribution base is converted to a form, which canbe inputted to the linear programming means shown in FIG. 32 using thecontents of the supply and demand table of FIG. 31. (This tablesummarizes transport costs between the place of supply "Si" and theplace of demand "Di".)

In FIG. 32, sum of products of pallet quantity Xij to be forwarded fromthe place of supply "i" to the place of demand "j" and transport costfrom the place of supply "i" to the place of demand "j" is expressed inmathematical equations. Also, the fact that total sum of the pallets tobe forwarded from each place of supply "i" is less than the quantity ofpallets in excess on the first day at the place of supply "i" and thattotal sum of the pallets to be forwarded to each place of demand "j" ismore than the quantity of pallets in shortage on the first day at theplace of demand "j".

In Step 1220, the data needed on the first day is inputted to the linearprogramming means, and it is calculated in such manner that sum ofproducts of pallet quantity and transport cost takes the minimum value.Then, the results shown in FIG. 33 are outputted by the linearprogramming means in Step 1230.

In Step 1235, this is converted to the data of number of servicesbetween the physical distribution bases shown in FIG. 34. The data isadded by converting the first day to calendar day, and the data of theresults obtained in Step 1240 is stored in the storage area 19.

Next, in Step 1250, it is judged whether the period in question has beenterminated or not. If terminated, the data of the storage area 19 isoutputted in Step 1260 to the storage unit 33 where the planning resultsare stored, and the processing is completed. If the period is not yetterminated, returning to Step 1220, the number of services on the nextday is determined.

When determining the number of forwarding services on the next day, theplanning results of the preceding day are reflected to the demandquantity of pallets. As described above, the forwarding service judgingmeans 12 sets up detailed pallet forwarding plan using linearprogramming method, determines number of forwarding services andquantity of forwarding pallets and presents them to the user. Toidentify the predicted quantity of pallets present at the physicaldistribution base, the user starts the pallet quantity predicting means13. The pallet quantity predicting means 13 predicts quantity of palletscurrently present at each physical distribution base according to theflow chart of FIG. 18.

When started by UI 20 in Step 1300, the pallet quantity predicting means13 reads, for example, transport schedule to enter or leave the physicaldistribution base (in this case, Asahikawa) shown in FIG. 35, andquantity of pallets to be forwarded by transport service from the datastored in the initial data storage unit 31, the actual result datastorage unit 32 and the planning result storage unit 33, and also readsthe quantity of pallets to be forwarded to each physical distributionbase under the forwarding plan, the delivery schedule interval and thestandard stock quantity.

When the date "November 29" to be simulated and the name of the physicaldistribution base "Asahikawa" are inputted from UI 20 in Step 1320, thepallet quantity predicting means 13 calculates in Step 1330 time seriesdata of the pallet quantity on the specified day at the specifiedphysical distribution base from the data thus read and analyzes this toobtain a function, which approximates variation of pallet quantity onone day. The result is stored in the planning result storage unit 33 andis displayed as shown in FIG. 19 via UI 20, and the processing iscompleted in Step 1340.

As described above, the pallet quantity predicting means 13 presentsdaily variation of pallet quantity at the specified physicaldistribution base in comparison with the standard stock quantity. If thepallet quantity is more than the standard stock quantity, it means thatpallets are in excess. If it is lower than the standard stock quantity,pallets are in shortage.

When actual pallet quantity (actual value) at each physical distributionbase has been identified, and if the quantity is different from thepredicted quantity of pallets (planned quantity) needed, the user startsthe actual result feedback means 14 and sets up the pallet forwardingplan to fill the gap. In this case, the actual result feedback means 14operates according to the flow chart of FIG. 20, and the forwarding planis determined.

When started by UI 20 in Step 1400, the actual result feedback means 14reads in Step 1410 standard stock quantity data at each physicaldistribution base, complementary difference quantity between plannedpallet quantity and actual quantity (difference between planned quantityand actual quantity) as shown in FIG. 36 and transport cost betweenphysical distribution bases shown in FIG. 30 from the data stored in theinitial data storage unit 31, the actual result data storage unit 32 andthe planning result storage unit 33 into the storage area 19.

Next, the actual feedback means 14 executes the same procedure (Steps1415 to 1416) as the procedure after Step 1215 in case of setting of thepallet forwarding plan (FIG. 17), and the planning results correspondingto FIG. 34 are outputted. The planning results are stored in theplanning result storage unit 33 or are presented to the user via UI 20.When the schedule interval of the pallet forwarding service is set to 2days, for example, the user starts the schedule interval judgmentsupporting means 15A to find out how the pallet forwarding plan ischanged. The schedule interval judgment supporting means 15A operatesaccording to the flow chart of FIG. 21 and presents to the user thepallet forwarding plan when the schedule interval of pallet forwardingservice is set to the specified number of days.

When started by UI 20 in Step 1500A, the schedule interval judgmentsupporting means 15A reads in Step 1510A, for example, the standardstock quantity data at each distribution base and quantity in excess orshortage of pallets for 3 days shown in FIG. 37 and transport costbetween distribution bases shown in FIG. 38 into the storage area 19based on the data stored in the initial data storage unit 31; the actualresult data storage unit 32 and the planning result storage unit 33.Also, the schedule interval specified by the user, i.e. 2 days, isstored in the storage area 19 as parameter.

In Step 1520A, it is supposed that the initial value i=0, and schedulecounter value is calculated. In Step 1522A, it is judged whether thecounter value is equal to the specified schedule interval, i.e. 2 days,or not. If it is equal, the quantity in excess or shortage on the firstday is added to that of the second day in Step 1521A.

In Step 1520A, the schedule counter value is equalized on the secondday, and it is converted in Step 1524A to a form which can be inputtedto linear programming means shown in FIG. 39 with respect to thequantity in excess or shortage on the second day, and it is inputted tothe linear programming means in Step 1525A.

In Step 1530A, the value of FIG. 40 is outputted from the linearprogramming means. In Step 1533A, this is converted to the data of thenumber of services between the physical distribution bases. The data isadded to convert the first day to calendar day. In Step 1540A, theresults are stored into the storage area 19. In Step 1550A, it is judgedwhether the period in question has been terminated or not. If notterminated, return to Step 1520A. If terminated, the data of the storagearea 19 is outputted to the planning result storage unit 33, and theprocessing is terminated is Step 1560A.

After the completion of the processing, the planning result is displayedon UI 20. If the user is not satisfied, the parameter of the scheduleinterval is changed, and the schedule interval judgment supporting means15A is started again. Also, to set the schedule interval of palletforwarding to the optimal value, the user starts the schedule intervalautomatic judging means 15B. The schedule interval automatic judgingmeans 15B operates according to the flow chart of FIG. 22, and theschedule interval of pallet forwarding is determined.

When started by UI 20 in Step 1500B, the schedule interval automaticjudging means 15B reads the data of maximum value of the initializedschedule interval (e.g. 15) from the initial data storage unit 31 asdefault value. In Step 1530B, the schedule interval is set to 1, andthis is stored into the storage area 19 in Step 1540B. In Step 1550B,the schedule interval supporting means 15A is started, and the palletforwarding plan at the preset schedule interval is calculated.

In Step 1555B, output of the schedule interval support means 15A isjudged by dichotomy. Maximum value of schedule interval is obtained insuch range that the number of pallet forwarding services does not exceeda predetermined value. The schedule interval is set again, and theprocedure of Step 1530B and after is repeated. If maximum value isobtained, the maximum value as well as the schedule interval at thattime and the schedule are outputted as the planning result, and theprocessing is completed in Step 1560B.

Then, the schedule interval automatic judging means 15B presents thepallet forwarding plan when the schedule interval of the palletforwarding services is set to the optimal value to the user. Also, toidentify the pallet quantity to be prepared at physical distributionbase, the user starts the standard stock quantity judgment supportingmeans 16A. The standard stock quantity judgment supporting means 16Aoperates according to the flow chart of FIG. 23.

When started by UI 20 in Step 1600A, the standard stock quantityjudgment supporting means 16A reads in Step 1610A the transport servicetimetable shown in FIG. 41 and the data of pallet loading ratio (e.g.average loading ratio=60; average pallet quantity varying ratio=0.1)from the initial data storage unit 31.

In Step 1620A, tile standard stock quantity judgment supporting means16A calculates pallet quantity (difference from the standard stockquantity) at every hour as shown in FIG. 42 based on the timetable andthe loading ratio of FIG. 41. In Step 1630A, the quantity of pallets intime zone when the pallet quantity reaches minimum within a day isdetected, and it is judged whether the minimum value is positive ornegative. If negative, the quantity to be prepared is determined in Step1635A as pallet quantity minimum value * (1+varying ratio), and it isstored into the storage area 19 in Step 1660A.

If the minimum value is positive in Step 1630A, it is judged in Step1640A whether the value "Max (pallet quantity) -{Max (pallet quantity)-Min (pallet quantity)} * variation ratio" is positive or negative. Incase of Sapporo, if it is supposed that 30 at 2:00 is minimum and 150 at3:00 is maximum, the value is 18. If this value is negative, absolutevalue of this is determined as the quantity to be prepared in Step1650A.

If it is positive in Step 1645A, the quantity to be prepared isconsidered as 0. In the example of Sapporo, the quantity of pallets tobe prepared is 0. In Step 1670A, this is repeated by the number of thedays in the planned period. When the sum of the quantity to be preparedin the whole schedule and the initial value of the standard stockquantity is maximum, this is considered as the standard stock quantityin the planned period. In Step 1680A, the user confirms the results byUI 20 and stores the results in the initial data storage unit 31, andthe processing is completed.

Also, to identify the pallet forwarding plan when the standard stockquantity at a certain physical distribution base has been changed, theuser starts the standard stock quantity automatic judging means 16A. Inthis case, the standard stock quantity automatic judging means 16Aoperates according to the flow chart of FIG. 24.

An example is given on the case where the standard stock quantity atUrawa is changed. When started by UI 20 in Step 1600B, the standardstock quantity automatic judging means 16B reads in Step 1610B defaultvalue of the standard stock quantity at each physical distribution baseas shown in FIG. 43 and the standard stock quantity and the quantity inexcess or shortage at each physical distribution base shown in FIG. 45as the initial data. In the data of quantity in excess or shortage ofFIG. 45, the standard stock quantity is a variable. Next, in Step 1620B,the changed value of the standard stock quantity at Urawa (Urawa: 400)is read.

In Step 1630, the standard stock quantity automatic judging means 16Bchanges the data of the quantity to be prepared using the standard stockquantity judgment supporting means 16A. Base on this data; the data ofthe quantity in excess or shortage shown in FIG. 45 is changed as shownin FIG. 46. In Step 1640B the excess/shortage table is stored in thestorage area 19. In Step 1650B, the schedule interval judgmentsupporting means 15A is started. In this case, the schedule intervaljudgment supporting means 15A does not read the excess/shortage tablefrom the initial data storage unit 31 as the initial value, but, usingthe excess/shortage table on the storage area 19, it executes theprocedure of FIG. 21 and presents the optimal value of the scheduleinterval in the pallet forwarding services and the pallets forwardingplan. The user confirms the results by UI 20, and the processing iscompleted in Step 1660B. If the user is not satisfied, the change valueof the standard stock quantity is changed again, and the user starts thestandard stock quantity judging means 16B.

When setting the pallet forwarding services, the user starts thehierarchical planning means 17. The hierarchical planning means 17operates according to the flow chart of FIG. 25. When started by UI 20in Step 1700, the hierarchical planning means 17 reads the initial datashown in FIG. 47, for example, from the data stored in the initial datastorage unit 31, the actual result data storage unit 32 and the planningresult storage unit 33. In the data of FIG. 47, the physicaldistribution bases are classified into 3 regional delivery districts ofTohoku, Kanto and Kyushu, and there are places of Sendai/Morioka/Aomori,Maebashi/Urawa/Yokohama and Fukuoka/Saga/Oita in these districtsrespectively.

In Step 1720, the hierarchical planning means 17 starts the forwardingservice judging means 12 and determines pallet forwarding services foreach district. In Step 1730, pallet forwarding services between thebases in each district are determined as shown in FIG. 48 by theforwarding service judging means 12. The solution is outputted as theplanning results, and the processing is completed in Step 1740.

As described above, the hierarchical planning means 17 sets up thepallet forwarding plan to match the hierarchical structure of the widearea physical distribution network. Also, the actual result dataautomatic collecting means L8 collects actual result data of the palletsaccording Lo the flow chart of FIG. 26 and changes them to necessarydata.

When started by the time control means in Step 1800, the actual dataautomatic collecting means 18 reads the actual result data shown in FIG.49, for example, from the wireless tag device 41 in Step 1810. In Step1820, these data are processed and are changed to the data shown in FIG.36.

When all data are changed in Step 1830, these data are stored in theactual result data storage unit 32, and the processing is completed inStep 1840.

As it is evident from the above description, it is possible according tothe system for controlling physical distribution pallets of the presentinvention to carry out stock control of pallets in wide area physicaldistribution in uniform and easy manner. It is also possible toaccurately predict supply and demand of pallets and to set up aforwarding plan to minimize forwarding cost of the pallets, and further,to find out the optimal transport route to the forwarding destination.As a result, wide area physical distribution can be accomplished insmooth manner.

Also, it is possible according to the system for controlling physicaldistribution pallets of the present invention to set up a palletforwarding plan and to present useful control information to cope withdiversified requirements. Specifically, the present system not onlymakes it possible to set up a detailed pallet forwarding plan for agreat number of physical distribution bases, but also to promptlypresent pallet forwarding plan for a small number of physicaldistribution bases.

Also, the present system can predict and present the changes over timeof pallet quantity at each physical distribution base. Further, it ispossible to set up a pallet forwarding plan to accomplish the forwardingof the planned quantity based on the actual result data of the pallets.

Further, it is possible according to the present system to simulate thepallet forwarding plan when schedule interval of the pallet forwardingservices is changed and to set the optimal schedule interval based onsuch simulation. In addition, it is also possible to present thequantity of pallets to be prepared as the standard stock at eachphysical distribution base and to show the pallet forwarding plan incase the standard stock quantity is changed.

Also, it is possible by the present system to set up a pallet forwardingplan to match hierarchical structure of the wide area physicaldistribution network.

What is claimed is:
 1. A system for controlling physical distributionpallets used for transportation of freight in wide area physicaldistribution, comprising:a wireless tag mounted on each pallet, saidwireless tag storing pallet control information of the pallet andoperable for transmitting said pallet control information in wireless byradio wave energy which is generated in said wireless tag; wirelessdetecting means installed at each of a plurality of physicaldistribution bases for detecting pallet control information transmittedfrom the wireless tag mounted on each pallet arriving at or departingfrom a respective physical distribution base; stock data storage meansfor receiving and storing the pallet control information detected bysaid wireless detecting means via a wide area communication network;pallet status judging means for judging whether a pallet stored in saidpallet stock data storage means is empty or not based on the palletcontrol information of said pallet; transport schedule storage means forstoring information relating to a schedule of transport services andsupply; and demand predicting means for predicting supply and demand ofpallets at said physical distribution base according to the informationstored in said transport schedule storage means and according to aquantity of pallets in an empty status at the physical distributionbase, further comprising forwarding plan setting means for setting up apallet forwarding plan between the physical distribution bases accordingto the predicted supply and demand data of pallets obtained by saidsupply and demand predicting means and knowledge or constraint conditionrelating to supply and demand of pallets.
 2. The system for controllingphysical distribution pallets according to claim 1, wherein saidforwarding plan setting means sets up forwarding destination, forwardingquantity and forwarding time to minimize a forwarding cost between aplurality of physical distribution bases where pallets are in excess anda plurality of physical distribution bases where pallets are inshortage.
 3. The system for controlling physical distribution palletsaccording to claim 1, further comprising transport network storage meansfor hierarchically arranging and storing information relating to atransport network connecting said physical distribution bases,andwherein said forwarding plan setting means uses data stored in saidtransport network storage means when setting up said pallet forwardingplan.
 4. The system for controlling physical distribution palletsaccording to claim 3, wherein said transport network storage meansclassifies data relating to said transport network into major transferbases, general transfer bases and collection and delivery basesaccording to a function of each physical distribution base andhierarchically stores said data.
 5. The system for controlling physicaldistribution pallets according to claim 1, further comprising:mapstorage means for storing road maps, and route searching means forsearching a transport route to said pallet forwarding destination basedon the data of the pallet forwarding plan set up by said forwarding plansetting means and the data of said map storage means.
 6. A system forcontrolling physical distribution pallets for controlling a stock ofpallets and for setting up a pallet forwarding plan in wide areaphysical distribution comprising:a user interface for accepting requestof a user and for displaying the pallet forwarding plan thus set up; awireless tag device for automatically acquiring information relating toentry or departure of pallets to or from stock, said wireless tag deviceoperable for transmitting said information in wireless by radio waveenergy which is generated in said wireless tag device; accumulatingmeans for accumulating information of acquired pallets or information ofthe pallet forwarding plan thus set up; and a system main unit forreading information of said accumulating means and for setting up thepallet forwarding plan requested by the user, wherein said system mainunit comprises hierarchical planning means for dividing physicaldistribution bases into bases between districts and bases within adistrict and hierarchically setting up said pallet forwarding plan intoa plan between districts and a plan within a district.